Answer:
<h2>0</h2>
Step-by-step explanation:
When drawing a triangle, note that the vectors can be drawn either in a clockwise or anticlockwise direction. For a triangle with vertices A, B and C, te vectors are AB, BC and CA
In vector notation CA = - AC (length CA is equal to AC but acting in opposite direction to AC)
and AB+BC = AC
To evaluate AB + BC + CA, we will substitute the vector expression above into the given expression and simplify as shown;
= (AB + BC) + CA
= AC + (-AC)
open the parenthesis
= AC-AC
= 0
<em>Hence the sum of the vector expression AB + BC + CA is a zero vector</em>